Disposable pump and filter assembly

ABSTRACT

Disclosed herein is a disposable combination pump/filter assembly to simultaneously dispense and filter aseptic solutions. The disposable pump and filter assembly includes a piston assembly incorporating a piston rod and a piston head, a pump head assembly with inlet and outlet ports, a vacuum chamber, a rolling diaphragm seal, a filter element, intake and discharge valve mechanisms, flexible intake/discharge tubing, and a clamping assembly that holds the head, diaphragm, and vacuum chamber together. The assembly minimizes the total number of individual parts that make up the pump and filter assembly, as well as the cost to manufacture.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application derives priority from U.S. Provisional Patent Application No. 60/235,686 for “DISPOSABLE PUMP AND FILTER ASSEMBLY”; Filed Sep. 27, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to liquid filling pumps, and more particularly, to an improved disposable pump with integral filter assembly.

[0004] 2. Description of the Background

[0005] The production of aseptic, pharmaceutical solutions is subject to many technical challenges. Typically, two separate systems are required for the filling and filtration processes, and both are complex and costly. The costliness is attributed to the design and materials (e.g. stainless steel and special heat/moisture resistant plastics) used to create an assembly capable of withstanding the rigors of repeated autoclaving—a process that subjects the assembly's components to a temperature of 121° C. for a period of thirty minutes. In addition, it is more cumbersome to maintain the two separate filling and filtration systems. The pump assemblies used in the filling process require frequent and thorough cleaning procedures, and there is a need for frequent replacement of filter elements. In addition to the technical challenges, a great deal of procedural documentation must be created and maintained current to satisfy certain regulatory requirements. Each time that a filling or filtration component is replaced, the replacement unit must be accompanied by appropriate validation documentation.

[0006] U.S. Pat. No. 4,369,898 to Andersson shows a filling machine with a filter mounted in the outlet conduit of a quantitation pump, and a valve in the supply conduit leading to the quantitation pump, and adapted, at will, to interrupt the connection between the source supplying the liquid product. The valve allows the filters to be checked when the filling is terminated, to establish that no filter has been damaged. Such checking is performed by a bubble-point test (pressure for forcing a column of liquid through the capillaries of the filter is measured).

[0007] It would be greatly advantageous to provide a disposable combination pump/filter assembly to simultaneously fill and filter aseptic solutions, and which combines the filling and filtration processes in a single disposable component to reduce the onerous process of keeping all validation documentation up-to-date.

SUMMARY OF THE INVENTION

[0008] It is, therefore, an object of the present invention to provide a disposable combination pump/filter assembly to simultaneously fill and filter aseptic solutions.

[0009] It is another object of the present invention to provide a disposable combination pump/filter assembly designed to withstand a finite number of autoclaving cycles prior to disposal.

[0010] Still another object of the present invention is to provide a disposable combination pump/filter assembly that assists in reducing the onerous process of keeping all validation documentation up-to-date.

[0011] It is yet another object of the present invention to provide a disposable combination pump/filter assembly that is economical to manufacture.

[0012] In accordance with the above objects, an improved disposable pump and filter assembly according to the present invention includes a piston assembly incorporating a piston rod and a piston head, a pump head assembly with inlet and outlet ports, a pump housing enclosing a vacuum chamber, a rolling diaphragm seal, a 0.22μ (i.e. micron) filter element, intake and discharge valve mechanisms, flexible intake/discharge tubing, and a clamping assembly that holds the pump head, diaphragm seal, and pump housing together.

[0013] By combining the filling and filtering functions, the present invention minimizes the total number of individual parts that constitute the pump and filtering processes. The cost to manufacture the present invention is minimized by using materials capable of withstanding only a limited number (e.g. 10 to 15) of autoclave cycles. Documentation maintenance is aided by providing certification that the present invention was manufactured in a facility operating in accordance with quality system guidelines based on current good manufacturing procedures (i.e. cGMP's) and supplying each combination pump and filter assembly in a sealed sterile package.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment and certain modifications thereof when taken together with the accompanying drawings in which:

[0015]FIG. 1 is an exploded view of the improved disposable pump with integral filter assembly 100 according to the present invention.

[0016]FIG. 2 is a front perspective, cross-sectional view of the improved disposable pump with integral filter assembly 100 as in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017]FIG. 1 is a front, cross-sectional view of the improved disposable pump with integral filter assembly 100 according to the present invention. The disposable pump with integral filter assembly 100 generally includes a pump housing 5 defining an internal vacuum chamber 10, and a pump head assembly 20 mounted atop the pump housing 5. The head assembly 20 includes a fluid intake port 22 and a discharge port 24. A rolling diaphragm 30 is seated within the vacuum chamber 10 for inducting fluid into the fluid intake port 22 and expelling it from discharge port 24. A filter element 60 resides within the pump head assembly 20 in order to filter the passing fluid. By combining the pumping and filtering functions, the present invention minimizes the total number of individual parts that constitute the pump and filtering processes. The cost to manufacture the present invention is minimized by using materials capable of withstanding only a limited number (e.g. 10 to 15) of autoclave cycles.

[0018] The pump head assembly 20 is mounted atop the pump housing 5 and the vacuum chamber 10. The head assembly 20 includes a fluid intake port 22 which is preferably an integrally-molded extended hose coupling, and a like discharge port 24.

[0019] Fluid is inducted into fluid intake port 22 by a piston assembly 70 which includes a piston rod 72 and a piston head 74, and a rolling diaphragm 30 maintained in a constantly extended state within the vacuum chamber 10. During an operational cycle the piston rod 72 and head 74 rise upward against the rolling diaphragm 30, effectively turning the rolling diaphragm 30 “inside-out.”

[0020]FIG. 2 is a front, exploded view of the disposable pump with integral filter assembly 100. The pump housing 5 defines a generally cylindrical vacuum chamber 10. Pump housing 5 may be formed of stainless steel or of molded plastic composite. The rolling diaphragm 30 is formed as a unitary flexible cup-shaped member that is supported inside vacuum chamber 10 by a seal ring 35 which encircles its rim. In this regard, the top end of the pump housing 5 is defined by an annular recess around the vacuum chamber 10, and the head assembly 20 is likewise configured, thereby providing a circular channel when clamped together to seat the seal ring 35 and provide a watertight seal. The head assembly 20, seal ring 35 of the rolling diaphragm 30, and pump housing 5 are clamped together using a head retainer clamp 40 (see FIG. 1). A variety of clamping mechanisms may be well-suited for use as the head retainer clamp 40. Preferably, head retainer clamp 40 is a quick-release design to provide “quick changeover” capability for size changes and/or cleaning purposes, and to provide ergonomic assistance for the re-assembly process.

[0021] The pump head assembly 20 is preferably a molded plastic component that includes intake port 22 and discharge port 24 in addition to the concave molded bottom edge discussed above. The intake and discharge ports 22, 24 provide the means for connecting standard intake tubing 50 and discharge tubing 52 to the combination pump and filter assembly. The head assembly 20 also serves as a housing for an integral filter element 60.

[0022] The rolling diaphragm 30 comprises a silicone inner surface adhered to a fabric backing. The silicone material provides a surface that can be sterilized while the fabric backing furnishes the strength required to withstand many (i.e. 1,000,000+) operational pump cycles. This two-part design is important because each operational cycle requires the rolling diaphragm 30 to turn itself “inside-out.” As stated above, the rolling diaphragm 30 includes seal ring 35 which is integrally molded into its top rim. The seal ring 35 provides both a liquid-tight (i.e. with respect to the liquid passing through the pump) and an air-tight seal (i.e. with respect to the vacuum present in the vacuum chamber) when clamped in place between the vacuum chamber 10 and the head assembly 20.

[0023] The filter element 60 is positioned within the head assembly 20 such that its filtering function occurs only during the discharge cycle of the pump assembly 100 (e.g., it separates the inlet and outlet ports, for instance, only covering discharge port 24). Preferably, a filter element 60 is used that is designed to capture all particulate matter larger than 0.22μ (i.e. microns) in size that enters the pump 100. Particulate matter of this size typically includes germs and spores.

[0024] As stated above, piston assembly 70 includes piston rod 72 and a piston head 74. The piston assembly 70 is cycled by a prime mover such as a conventional servo or DC motor assembly (not shown in the Figures). The piston rod 72 is typically fabricated of stainless steel while the piston head 74 is generally fabricated of a non-metallic, autoclavable material. The piston head 74 conforms to the piston rod 72 but is not directly attached. However, the downward force exerted on the piston head 74 by the vacuum, present in the vacuum chamber 10, acting on the backside of the rolling diaphragm 30 keeps it in contact with piston rod 72 at all times.

[0025] The combination pump and filter assembly 100 also includes intake and discharge valves 80, 82, respectively, that incorporate a pinch clamp design. Intake pinch clamp valve 80 and discharge pinch clamp valve 82 each comprise a pneumatic cylinder (not shown in the Figures) to apply the pressure to the intake tubing 50 and the discharge tubing 52, respectively, required to impede the flow of liquid. Suitable pinch valves are commercially available from, among others, Acro Associates of Concorde, Calif.

[0026] With combined reference to FIGS. 1 and 2, an operational cycle of the pump and filter assembly 100 begins with the piston assembly 70 in the up position, the rolling diaphragm 30 in an “inside-out” configuration, and both pinch clamp valves (i.e. intake 80 and discharge 82) in the closed position. Downward motion of the piston assembly 70, coupled with the vacuum present in the vacuum chamber 10 and the opening of the intake pinch clamp valve 80, causes the movement of liquid into the combination pump and filter assembly 100 through intake tubing 50 and intake port 22. At the end of the piston assembly's downward motion, the rolling diaphragm 30 has returned to its normal configuration (as shown) and intake pinch clamp valve 80 closes. Upward motion of the piston assembly 70, coupled with the vacuum present in the vacuum chamber 10 and the opening of the discharge pinch clamp valve 82, causes the movement of liquid through the filter element 60 and out of the combination pump and filter assembly 100 through discharge tubing 52 and discharge port 24. At the end of the piston assembly's upward motion, the rolling diaphragm 30 is once again in the “inside-out” configuration and discharge pinch clamp valve 82 closes.

[0027] The above-described combination pump/filter assembly simultaneously and efficiently fills and filters aseptic solutions. Moreover, it can be economically manufactured for disposal after a finite number of autoclaving cycles, thereby reducing the onerous process of keeping all validation documentation up-to-date.

[0028] Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims: 

We claim:
 1. A combination pump/filter assembly to pump and filter fluids, comprising: a pump housing defining a central chamber; a diaphragm seated in said central chamber; a piston assembly operative within said central chamber for engaging said diaphragm; a pump head assembly mounted on said pump housing over said central chamber; said pump head assembly having an inlet port and an outlet port; an inlet valve for controlling flow through said inlet port; an outlet valve for controlling flow through said outlet port; and a filter element separating said inlet and outlet ports of said pump head assembly for filtering fluids passing there between.
 2. The disposable combination pump/filter assembly according to claim 1, further comprising a clamping assembly that holds said pump head assembly and said pump housing together.
 3. The disposable combination pump/filter assembly according to claim 1 wherein said pump housing further comprises a top end formed with an annular recess.
 4. The disposable combination pump/filter assembly according to claim 1, wherein said pump head assembly mounted on said pump housing produces a vacuum force that is exerted on said rolling diaphragm and piston assembly thereby maintaining operative engagement there between.
 5. The disposable combination pump/filter assembly according to claim 1 wherein said piston assembly further comprises a piston rod and piston head seated on one end of said piston rod, the other end of the piston rod being operatively coupled to a prime mover.
 6. The disposable combination pump/filter assembly according to claim 5 wherein said prime mover is a motor drive assembly.
 7. The disposable combination pump/filter assembly according to claim 1 wherein said pump head assembly further comprises a concave bottom.
 8. The disposable combination pump/filter assembly according to claim 7 wherein said pump head assembly is formed from molded plastic.
 9. The disposable combination pump/filter assembly according to claim 1 further comprising an inlet tube attached to said inlet valve, and an outlet tube attached to said outlet port.
 10. The disposable combination pump/filter assembly according to claim 9, wherein said inlet and outlet valves comprise pinch clamps for applying pressure to the respective inlet and outlet tubes to selectively impede the flow of liquid there through.
 11. The disposable combination pump/filter assembly according to claim 1 wherein said rolling diaphragm seal further comprises a top rim formed as a seal ring; said seal ring providing an air- and liquid-tight seal when clamped between said annular recess of said pump housing and said concave bottom edge of said pump head assembly.
 12. The disposable combination pump/filter assembly according to claim 11 wherein said rolling diaphragm seal further comprises an elastomeric inner surface adhered to a fabric backing.
 13. The disposable combination pump/filter assembly according to claim 12 wherein said elastomeric inner surface is silicone.
 14. The disposable combination pump/filter assembly according to claim 1 wherein said filter element is operative only during a discharge cycle of said combination pump/filter assembly.
 15. The disposable combination pump/filter assembly according to claim 1 wherein said filter element is configured for use with aseptic liquids.
 16. The disposable combination pump/filter assembly according to claim 15 wherein said filter element further comprises a 0.22μ filter.
 17. The disposable combination pump/filter assembly according to claim 1 wherein said clamping assembly further comprises a quick-release clamping assembly.
 18. A disposable combination pump/filter assembly to simultaneously fill and filter aseptic solutions, comprising: a pump housing defining a central vacuum chamber; a piston assembly incorporating a piston rod and a piston head operative within said central vacuum chamber at one end; a pump head assembly mounted on said pump housing over said central vacuum chamber, said pump head assembly having inlet and outlet ports; a first length of flexible tubing removably attached to said inlet port; a second length of flexible tubing removably attached to said outlet port; an inlet valve mechanism operatively engaged with said first length of flexible tubing; an outlet valve mechanism operatively engaged with said second length of flexible tubing; a rolling diaphragm seal separating said pump head assembly from said central vacuum chamber; a filter element separating said inlet and outlet ports of said pump head assembly; and a clamping assembly that holds said pump head assembly, said rolling diaphragm seal, and said pump housing together.
 18. The disposable combination pump/filter assembly according to claim 1 wherein said pump housing is formed with a cylindrical inner recess.
 19. The disposable combination pump/filter assembly according to claim 17 wherein said rolling diaphragm seal further comprises a top rim formed as a seal ring.
 20. The disposable combination pump/filter assembly according to claim 1 wherein said filter element is an aseptic filter that is operative only during a discharge cycle of said combination pump/filter assembly. 